Over the years, many different types of bags, pouches, and wraps have been used for carrying food, such as sandwiches and snacks. Of these, a variety of types have emerged over the years, such as plastic sandwich bags, cellophane, foil and wax paper wraps, and sturdy, reusable containers, e.g., Tupperware® style plastic containers. (Tupperware is a registered trademark of Dart Industries Inc.). There are also some fabric sandwich bags. Of these types, many sandwich bags and plastic containers have closures of various types.
Some plastic sandwich bags have a “zip” style closure, while others have a fold and pocket style closure. Fabric sandwich bags have zip-style closures or Velcro® closures. (Velcro is a registered trademark of Velcro Industries, B.V.) The various types of bags are not sturdy, so the food inside can be damaged, e.g., squished sandwiches or fruit, broken cookies or crackers, and so on. The sturdy plastic containers have a snap-style closure that are generally made to be airtight. These containers are 2-piece, a container and a lid that snaps onto the container. These tend to protect their contents, but they are severally constrained by their rigidity in terms of what they can hold. For example, an apple would not fit in a rigid plastic sandwich containers.
To date, people have adapted to these available options. Many people use wraps, sandwich bags, and rigid plastic containers of various sizes and draw on these different types of containers as needed. In many situations, this may not be ideal, since rigid containers can be bulky and take up a great deal of space in a child's lunchbox, for example. It is not unusual, therefore, to see children's lunchboxes that will not close, because the rigid plastic containers are too bulky. It is also not unusual to see a child's sandwich that was kept in a plastic bag or sandwich wrap deformed by lunchtime—often by a rigid plastic container with which it shared a lunchbox.